The Response Object (res)

The res object represents the HTTP response that an Express app sends when it gets an HTTP request.

Commonly Used Methods

Method	Purpose	Example
`res.send()`	Send a response of various types	`res.send('Done')`
`res.json()`	Send a JSON response (Best for APIs)	`res.json({ id: 1 })`
`res.status()`	Set the HTTP status code	`res.status(404)`
`res.render()`	Render a view template	`res.render('index')`
`res.redirect()`	Redirect to a different URL	`res.redirect('/login')`
`res.sendFile()`	Send a file as an octet stream	`res.sendFile(path)`

You can chain methods together to set a status and send data in one line.

app.get('/api/users', (req, res) => {
  res.status(201).json({ message: 'User created' });
});

Use res.redirect() to move users between pages, such as after a successful form submission.

app.get('/old-page', (req, res) => {
  res.redirect(301, '/new-page'); // Permanent redirect
});

Best Practice: Always use res.json() when building APIs, as it automatically sets the Content-Type to application/json.